1. Field of the Invention
The present invention relates to a structure for fixing a first and a second member together, and more particularly to a structure for fixing a first and a second member together between the head of a bolt and a nut threaded over an outer threaded end portion of the bolt.
2. Description of the Prior Art
Generally, in fixing a synthetic resin member such as a bumper to another member such as a support, a bolt and nut set has been used. The use of a bolt having a simple structure has often resulted in the bumper splitting or thermally deforming, thereby lowering the tightening of the bolt. Conventionally, in an attempt to overcome this problem, an ornamental bolt is inserted at a square stem portion thereof through holes in the bumper and a support through a sleeve, slightly shorter than the thickness of the bumper, positioned between the stem portion and the hole in the bumper. A washer is placed over the bolt, and then a nut is tightened over the threaded portion of the bolt, and the square stem portion of the bolt is engaged in the square hole in the support so as not to rotate in the square hole. The head of the bolt and the washer tightly hold the bumper and the support. In this case, excessive tightening force on the bolt and nut is received by the support through the sleeve and not applied directly to the bumper, thereby avoiding the above problem.
As another prior art fixing technique has been used an ornamental bolt which has a square stem inserted in complementary square holes in a bumper and a support. A spring washer is passed over the bolt, and then a nut is threaded over an outer threaded portion of the bolt and tightened against the bumper and the support. In this case, excessive tightening force on the bolt is borne by the washer, so that a constant tightening force only is applied to the bumper, thus solving the above problem. However, these structures require additional parts such as the sleeve and the washer thereby bringing about a relatively high cost of the structure as well as making the fixing relatively complicated.
It is an object of the present invention to provide a structure for fixing a first and a second member which prevents the loosening of a bolt without using any sleeve and special washer.
Another object of the present invention is to provide a structure for fixing a first and a second member which prevents a breakage in the first member, which may be for example a synthetic resin, and which brings about easy fixing of the first and second members.